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DCC Neutral zones

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Posted by dbduck on Sunday, October 17, 2010 12:15 AM

the layout when finish be around a room approx 20 x 40 It is being built in a basement that is 20 x 60

The loops are being built so that when its time to add another piece to the layout..they will simply be moved down abit & attached to  to the end of the new section 

The loops will not be attached to the wall..they will be free-standing "modules"

The initial piece of layout that they will be attached to is  20 feet long... an "L" that is 10ft on each side

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Posted by richhotrain on Sunday, October 17, 2010 12:25 AM

dbduck

the layout when finish be around a room approx 20 x 40 It is being built in a basement that is 20 x 60

The loops are being built so that when its time to add another piece to the layout..they will simply be moved down abit & attached to  to the end of the new section 

The loops will not be attached to the wall..they will be free-standing "modules"

The initial piece of layout that they will be attached to is  20 feet long... an "L" that is 10ft on each side

Wow, nice size layout when finished.  Now, it is all coming together what you are trying to do.  How long will your longest train be?  Can you build your temporary loops large enough to accomodate the longest train?  Are the engines the only rolling stock that can trip the auto-reverser?

Rich

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Posted by dbduck on Sunday, October 17, 2010 12:34 AM

I do not currently own any lighted passenger cars nor cabooses and if I did, I would not run them

The reason for making the loops small is because they are temporary..still they will prob be at least 28" radius

 Most trians would prob fit..but just in case..that is why I am doing what I am doing.

Also the loops are being built to accomodate the mains at any location (as close to the wall as possible or near the front edge) the loop module would just be brought out or slid back to line up

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Posted by dbduck on Sunday, October 17, 2010 12:38 AM

I like running long trains. When I run on a local module clubs layout I generally run at least 40+ cars to a train,.

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Posted by modelmaker51 on Sunday, October 17, 2010 2:45 AM

I just don't see that you have ANY reverse loops at all. According to your diagram, what you have are continuous loops, not reverse loops. If you do have a crossover from one loop to the other, the crossover would have to be insulated and separately fed from the buss, that's it, no reversers. Both loops have the same "polarity" or phase. This is essentially my setup. At the crossover I actually have double slips, allowing access from both mains to an inner yard track.

In my crude illustration the upper continuous loop would be called a dogbone in that configuration. The lower figure has two reverse loops and are not usually known as dogbones, but just reverse loops. Both reverse loops in the lower figure would be isolated as in the right loop.

Jay 

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Posted by richhotrain on Sunday, October 17, 2010 6:46 AM

modelmaker51

I just don't see that you have ANY reverse loops at all. According to your diagram, what you have are continuous loops, not reverse loops. If you do have a crossover from one loop to the other, the crossover would have to be insulated and separately fed from the buss, that's it, no reversers. Both loops have the same "polarity" or phase. This is essentially my setup. At the crossover I actually have double slips, allowing access from both mains to an inner yard track.

In my crude illustration the upper continuous loop would be called a dogbone in that configuration. The lower figure has two reverse loops and are not usually known as dogbones, but just reverse loops. Both reverse loops in the lower figure would be isolated as in the right loop.

http://img.villagephotos.com/p/2005-8/1069636/dogbone.JPG

modelmaker51,

That's what I thought too in the earlier phases of this thread.  From just reading the OP's words before finally seeing a drawing, I could not visualize a reversing  section or a reverse polarity issue.

But here is the issue. In your upper drawing, you isolate the crossover with gaps or insulated rail joiners to prevent a short due to reverse polarity.  That is what the rest of us would do as well.  The trouble is that the OP will eventually do away with the "loops" since the final layout will be an around-the-room double mainline continuous oval.  In the process of building the layout, he wants to wire both mainline tracks in phase with one another so the crossovers don't have to be gapped.

It is a matter of semantics.  Based upon the terminology used in the OP's initial posts, the solutions that you supplied make perfect sense.  But that is not what the OP wants to do.  Someone earlier in this thread suggested that the OP is going to have to do more work now to save work later, and that is true.  To tackle his task, the OP is building the around the room layout in modular form, moving the end "loops" in and out as modules until he eventually completes his oval. 

When I first read the initial post, I couldn't help but wonder why the OP didn't just complete the around the room benchwork, then lay the double mainline track in oval form, and be done with it.  But, given the size of the layout, it is apparent that the completion of the construction will have in stages, perhaps over a long period of time.

Rich

Alton Junction

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Posted by richhotrain on Sunday, October 17, 2010 6:56 AM

dbduck

I do not currently own any lighted passenger cars nor cabooses and if I did, I would not run them

The reason for making the loops small is because they are temporary..still they will prob be at least 28" radius

 Most trians would prob fit..but just in case..that is why I am doing what I am doing.

Also the loops are being built to accomodate the mains at any location (as close to the wall as possible or near the front edge) the loop module would just be brought out or slid back to line up

dbduck,

We have given you a lot of grief in responding to your initial post until that drawing finally emerged.  LOL.  In fact, you initially answered your own question about the dead zones to ensure the absence of problems with the temporary reversing sections.  What you propose to do will work, and I see no need to do anything different. 

I mentioned in my first post yesterday that I too have a double mainline oval with both mainline tracks wired in phase.  In that case, crossovers require no special treatment in terms of wiring.  Crossovers are simply wired in phase with the two mainline tracks.

Since the reversing sections will be temporary, it seems a shame to incur the cost of two auto-reversing units.  As others have pointed out, you could get away with one auto-reversing unit if the two "loops" are far enough apart to avoid confusing the single auto-reversing unit.  Another inexpensive solution for this temporary situation would be to control the reversing sections manually by installing toggle switches for each reversing section.

Rich

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Posted by modelmaker51 on Sunday, October 17, 2010 9:58 AM

I went back and looked at my crossings (I laid them 10 years ago) and they are in fact not isolated, but the loops (ovals) are for power distribution, however both loops are in phase.

The OP could use a dead section if he in fact had reversing section, but he doesn't have reversing sections, so he doesn't need it or a reverser. What he has are two sections of the ends of the ovals that are movable - no reversing. To have a reverse loop, a track has to loop around and reconnect with itself through a turnout, thus reversing the polarity of the rails at the turnout (see the lower illustration above). A crossing between the two ovals does not do that, all the rails are still the same polarity or phase, (in both loops/ovals).

Jay 

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Posted by richhotrain on Sunday, October 17, 2010 10:32 AM

modelmaker51

I went back and looked at my crossings (I laid them 10 years ago) and they are in fact not isolated, but the loops (ovals) are for power distribution, however both loops are in phase.

The OP could use a dead section if he in fact had reversing section, but he doesn't have reversing sections, so he doesn't need it or a reverser. What he has are two sections of the ends of the ovals that are movable - no reversing. To have a reverse loop, a track has to loop around and reconnect with itself through a turnout, thus reversing the polarity of the rails at the turnout (see the lower illustration above). A crossing between the two ovals does not do that, all the rails are still the same polarity or phase, (in both loops/ovals).

modelmaker51

I went back and looked at my crossings (I laid them 10 years ago) and they are in fact not isolated, but the loops (ovals) are for power distribution, however both loops are in phase.

The OP could use a dead section if he in fact had reversing section, but he doesn't have reversing sections, so he doesn't need it or a reverser. What he has are two sections of the ends of the ovals that are movable - no reversing. To have a reverse loop, a track has to loop around and reconnect with itself through a turnout, thus reversing the polarity of the rails at the turnout (see the lower illustration above). A crossing between the two ovals does not do that, all the rails are still the same polarity or phase, (in both loops/ovals).

So it seems, but the OP does, in fact, have two reversing sections, as illustrated in the following diagram:

I colored the two rails blue and red to show polarity.  He intends that the straight tracks form a double mainline when the large oval layout is complete.  He will wire both mainline tracks in phase with one another.  And, he wants his crossovers wired in phase with his mainline tracks so as to avoid reverse polarity problems and the need to gap the ends of the crossover(s).  So when he creates the temporary "loops" on either end, he has reverse polarity issues, as I have shown in the circled areas.

Rich

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Posted by modelmaker51 on Sunday, October 17, 2010 10:45 AM

I stand corrected. I misunderstood the OP's premise. You are correct, sir!Bow

Jay 

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Posted by richhotrain on Sunday, October 17, 2010 10:49 AM

modelmaker51

I stand corrected. I misunderstood the OP's premise. You are correct, sir!Bow

LOL

We all did, or at least most of us.  Some seemed to understand it from the initial post which, in itself, amazes me.

Rich

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Posted by DigitalGriffin on Monday, October 18, 2010 1:43 PM

Break into two power blocks.  One in red with a reversing section.  The other in gray.

Problem solved.

Don - Specializing in layout DC->DCC conversions

Modeling C&O transition era and steel industries There's Nothing Like Big Steam!

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Posted by richhotrain on Monday, October 18, 2010 5:31 PM

DigitalGriffin

Break into two power blocks.  One in red with a reversing section.  The other in gray.

Problem solved.

http://i52.photobucket.com/albums/g20/digital_griffin/solution.png

Ahem, dbduck is going to be mad at you.  He doesn't want to have to rewire his double mainline tracks once they are installed and wired the first time.   Super Angry   Super Angry   Super Angry

Rich

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Posted by dbduck on Monday, October 18, 2010 7:50 PM

I don't get mad..LOL 

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Posted by DigitalGriffin on Tuesday, October 19, 2010 12:05 PM

richhotrain

Ahem, dbduck is going to be mad at you.  He doesn't want to have to rewire his double mainline tracks once they are installed and wired the first time.   Super Angry   Super Angry   Super Angry

Rich

It's a lot simpler and solves all of his problems.

Don - Specializing in layout DC->DCC conversions

Modeling C&O transition era and steel industries There's Nothing Like Big Steam!

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Posted by DigitalGriffin on Tuesday, October 19, 2010 12:06 PM

richhotrain

Ahem, dbduck is going to be mad at you.  He doesn't want to have to rewire his double mainline tracks once they are installed and wired the first time.   Super Angry   Super Angry   Super Angry

Rich

It's a lot simpler and solves all of his problems.

Don - Specializing in layout DC->DCC conversions

Modeling C&O transition era and steel industries There's Nothing Like Big Steam!

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Posted by mobilman44 on Tuesday, October 19, 2010 2:37 PM

Hi!

I couldn't stand it anymore, had to say something...........

When I first read this post I was totally confused and puzzled.  That condition got significantly worse before it got better.  But when I got to the point that I thought I understood the situation, I decided that greater minds than mine needed to tackle this.

Whew................

ENJOY  !

 

Mobilman44

 

Living in southeast Texas, formerly modeling the "postwar" Santa Fe and Illinois Central 

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Posted by richhotrain on Tuesday, October 19, 2010 4:09 PM

DigitalGriffin

 richhotrain:

Ahem, dbduck is going to be mad at you.  He doesn't want to have to rewire his double mainline tracks once they are installed and wired the first time.   Super Angry   Super Angry   Super Angry

Rich

 

It's a lot simpler and solves all of his problems.

Actually, it doesn't, but I should let dbduck speak for himself.  But, what the heck, I will take a shot at this anyhow.  As he constructs his permanent layout, he wants to wire everything, that is everything, the same polarity including crossovers, and he doesn't want to gap the crossovers, even temporarily.  If you expand your diagram to include a crossover from the bottomsection of track to the top section of track, he would have to gap the crossover and he doesn't want to because in the final permanent layout there will be no gaps.

Hey, dbduck, you should pay me a commission for being your spokesman.   Laugh

Rich

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Posted by richhotrain on Tuesday, October 19, 2010 4:20 PM

mobilman44

Hi!

I couldn't stand it anymore, had to say something...........

When I first read this post I was totally confused and puzzled.  That condition got significantly worse before it got better.  But when I got to the point that I thought I understood the situation, I decided that greater minds than mine needed to tackle this.

Whew................

It is all dbduck's fault.  He had to propose this elegant solution to his construction problems and then leave it to the rest of us to arm wrestle over it.

 

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Posted by DigitalGriffin on Tuesday, October 19, 2010 4:42 PM

Well I hate to tell dbduck this, but you just about ALWAYS have to isolate the inner legs of all turnouts when doing DCC.

That's just the way it is.  So he'll have to double gap the crossover no matter what (sorry to report.)

www.wiringfordcc.com

look up the turnout section.  There's very few models that isolate the rails beyond the frog automatically.

 

 

Don - Specializing in layout DC->DCC conversions

Modeling C&O transition era and steel industries There's Nothing Like Big Steam!

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Posted by richhotrain on Tuesday, October 19, 2010 5:47 PM

DigitalGriffin

Well I hate to tell dbduck this, but you just about ALWAYS have to isolate the inner legs of all turnouts when doing DCC.

That's just the way it is.  So he'll have to double gap the crossover no matter what (sorry to report.)

www.wiringfordcc.com

look up the turnout section.  There's very few models that isolate the rails beyond the frog automatically.

 

Nah, you gotta read this thread in its entirety, and more closely.  When dbduck is done constructing his final layout, the temporary loops will be removed, and he will be left with a double mainline oval with crossovers, all wired in phase with one another, so the crossovers will not have to be gapped.

Rich

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Posted by DigitalGriffin on Tuesday, October 19, 2010 9:29 PM

richhotrain

Nah, you gotta read this thread in its entirety, and more closely.  When dbduck is done constructing his final layout, the temporary loops will be removed, and he will be left with a double mainline oval with crossovers, all wired in phase with one another, so the crossovers will not have to be gapped.

Rich

I did read it.  Temporary layout or not.  If you were feeding power by the points (a common dc method to direct power to one train at a time) it wouldn't be a problem.  However most switches on the market are NOT dcc friendly, because all the frog rails are active all the time this will not work.

Insulated frogs could be an option.  Or he could use switches that isolate automatically past the points rails.  He needs to read the article on wiring for dcc.  http://www.wiringfordcc.com/switches.htm 

But I will not twist his arm to try to convince him otherwise.  He'll figure it out on his own soon enough one way or the other.

 

Don - Specializing in layout DC->DCC conversions

Modeling C&O transition era and steel industries There's Nothing Like Big Steam!

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Posted by CSX Robert on Wednesday, October 20, 2010 5:40 PM

DigitalGriffin

Well I hate to tell dbduck this, but you just about ALWAYS have to isolate the inner legs of all turnouts when doing DCC.

That's just the way it is...

That depends entirely on the turnouts that you are using.

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Posted by Phoebe Vet on Wednesday, October 20, 2010 5:53 PM

DigitalGriffin

Well I hate to tell dbduck this, but you just about ALWAYS have to isolate the inner legs of all turnouts when doing DCC.

That's just the way it is.  So he'll have to double gap the crossover no matter what (sorry to report.)

www.wiringfordcc.com

look up the turnout section.  There's very few models that isolate the rails beyond the frog automatically.

I have 22 Atlas switches on my layout.  Snap switches, Custom line #4s and Custom line #6s.  None of them are gapped, and they all work fine on my Digitrax DCC layout.

Dave

Lackawanna Route of the Phoebe Snow

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Posted by floridaflyer on Wednesday, October 20, 2010 6:58 PM

Using the atlas customlines, you would only have to gap the turnouts if you wished to have separate power districts, one on the outer loop and one on the inner. He may want to think about  if he wishes to have his layout   broken into districts in the future.

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Posted by mfm37 on Wednesday, October 20, 2010 7:29 PM

DigitalGriffin

Well I hate to tell dbduck this, but you just about ALWAYS have to isolate the inner legs of all turnouts when doing DCC.

That's just the way it is.  So he'll have to double gap the crossover no matter what (sorry to report.)

 

 

If they short and need to be isolated, it's not because of DCC. DC will short too.  Peco electrofrogs would need to be insulated. Insulfrogs would not need to be insulated.

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Posted by DigitalGriffin on Wednesday, October 20, 2010 9:03 PM

Phoebe Vet

I have 22 Atlas switches on my layout.  Snap switches, Custom line #4s and Custom line #6s.  None of them are gapped, and they all work fine on my Digitrax DCC layout.

I think there's some confusion here in terminolgy that i need to clear up.  DCC friendly turnouts are automatically gapped past the frogs.  So no manual gapping is necessary.  I stated they have to be gapped, which is still true.

My appologies for any confusion I may have caused.

Don - Specializing in layout DC->DCC conversions

Modeling C&O transition era and steel industries There's Nothing Like Big Steam!

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Posted by rrinker on Wednesday, October 20, 2010 9:57 PM

 The real confusion is the use of the term DCC friendly here. Live frog or dead frog does not make or break DCC Friendly. A DCC Friendly turnout has the point and adjacent stock rail at the same polarity, so the back of a wheel brushing against the open point rail won't cause a short. In general, an unmodified power routing turnout will not be DCC Friendly because they rely on the point rail contacting the stock rail to pwoer the frog and the rails beyond. Power routing turnouts need gaps when hooked frog to frog, such as for a crossover. Non-power routing turnouts generally do not.

                --Randy


Modeling the Reading Railroad in the 1950's

 

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Posted by richhotrain on Thursday, October 21, 2010 6:32 AM

This thread has run far afield from the original issue posted by the OP.  Let's not lose sight of his question.

He is building a double mainline oval with crossovers, all wired in phase with one another.  He does not want to gap any crossovers so we may all infer that he intends to install "DCC Friendly" turnouts.

The only reason gapping ever came up is that he is temporarily installing reverse loops on either end of the double mainline effectively creating a dogbone layout.  As construction progresses, one of the reverse loops will be relocated further down the layout as the oval expands.

His only question was the recommended size of the gaps isolating the reversing sections. 

Having said that, Randy's explanation of the differences between DCC friendly and non-DCC friendly turnouts was superb, as usual.

Rich

 

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Posted by DigitalGriffin on Thursday, October 21, 2010 11:46 AM

richhotrain

The only reason gapping ever came up is that he is temporarily installing reverse loops on either end of the double mainline effectively creating a dogbone layout.  As construction progresses, one of the reverse loops will be relocated further down the layout as the oval expands.

His only question was the recommended size of the gaps isolating the reversing sections. 

Okay then these will HAVE to be the contraints:

1) He can have no tail end helper power

2) Each piece of motive power will have to have pickups on the left and right trucks for EVERY truck.  IE: Older engines that pick up left rail on the front truck and right rail on the rear will not work.

3) The isolating gap can not be longer than the length between the motive power trucks.  At the same time, if you have something like lighted passenger cars where the pickup is in the trucks, it wil have to be longer than those.  For example if the distance between the first and last trucks on the engine is 12" (first wheel to last wheel) and the distance between the trucks on the lighted passenger car is 11" (first wheel to last wheel) then the gap would have to be between 11.1 and 11.9"

As you can see it creates "issues" and lots of contraints on what you can and can not run.  This is why the recommend reverse loops be longer than your longest train.

 

Don - Specializing in layout DC->DCC conversions

Modeling C&O transition era and steel industries There's Nothing Like Big Steam!

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